Many neuropeptides originally isolated from the gastrointestinal system are also synthesized in the brain. Several of these "Brain- Gut" peptides have been shown capable of influencing the secretion of reproductive hormones from the anterior pituitary. Indeed, one of the major foci at recent meetings concerning the basic and clinical functions of these peptides, individually, has been their possible role in neuroendocrine regulation. Although the hypothesis that these centrally-derived peptides may play ar important role in neuroendocrine regulation is becoming widely accepted, the sites and mechanisms by which that regulation is exerted is poorly understood. Furthermore, elucidating the interactions occurring between these individual peptides as well as between central neurotransmitters and these peptide systems may be critical toward understanding the mechanisms of action by which these peptides exert their influence on reproductive hormone secretion. Therefore, the objectives of the proposed conference are to allow experts on the reproductive neuroendocrine functions of each individual "Brain-Gut" peptide to present a summary of recent advances concerning their particular peptide area, and to benefit from the insights provided by experts working with different peptides in attempting to formulate hypotheses about the participation of these peptides in reproductive neuroendocrine control.